A heads-up for those of you who track your 991s--be mindful of the fuel level. I normally don't stay on the track when the fuel level drops below 1/4 of a tank, but on occasion I'll run a couple of more laps before coming in. Running a bit below 1/4 of a tank was never an issue with my 2011 M3. But today with the 911 at NJMP Lightning I pushed it a bit, and got down to about 1/8 of a tank. The response was not good--in the Lightbulb, a big, sweeping bowl-shaped turn, the ECU must have detected the onset of fuel starvation and decided to cut power, putting the car in "limp" mode. So, imagine being in a large, sweeping turn, balancing the car on the edge of traction between understeer and oversteer at about 80mph, and suddenly having the ECU effectively hit the brakes by cutting power. Not fun. Luckily I sensed it and caught it before the back end could come around.

Lesson learned--when the tank gets to 1/4 full, come back in.

(Note: this was a new, different scenario compared to my previously- experienced PDCC faults on track. The PDCC faults occurred in constant, hi-G loading corners that seemed to overwhelm the PDCC sensors, regardless of fuel level. "PDCC fault--possible to drive on carefully" came on the display with those instances, and the ECU booted the car out of Sport Plus into Normal/"Comfort" mode, reducing throttle and suspension responsiveness, but NOT cutting power. This situation with low fuel today was distinct. Power was definitely cut, and something like "Engine fault--possible to drive on at reduced speed" was displayed.)

 

Thanks for the info. I've dipped below 1/4 on the track with the 911 quite a few times, but I never lower than 1/8th. I'm wary of these situations, especially since the indicator is not going to be accurate when you're going WOT for an extended period of time.

 

Also, if you do end up running out of fuel (or starving it in a turn), you can blow the fuel pump.

However, I think in the OP's case, there may be something askew with the ECU... I've gone very low in fuel on NJMP and other tracks (I'm not proud of it but in the heat of the moment in can be hard to stop) and I never had such an issue.

Great day for Lightning btw... I'm sure there was lots of speed!

 

Great driving!!

ChuckJ

 

I learned the same lesson at the Glen on turn 7. I was just below 1/4 tank, not fun. It scared me.

Frank C.

 

Another reason why we should all go out and buy electric cars ;-)